Obesity remains a serious health problem and it is no secret that many people want to lose weight. Behavioral economists typically argue that “nudges” help individuals with various decisionmaking flaws to live longer, healthier, and better lives. In an article in the new issue of Regulation, Michael L. Marlow discusses how nudging by government differs from nudging by markets, and explains why market nudging is the more promising avenue for helping citizens to lose weight.

Two long wars, chronic deficits, the financial crisis, the costly drug war, the growth of executive power under Presidents Bush and Obama, and the revelations about NSA abuses, have given rise to a growing libertarian movement in our country – with a greater focus on individual liberty and less government power. David Boaz’s newly released The Libertarian Mind is a comprehensive guide to the history, philosophy, and growth of the libertarian movement, with incisive analyses of today’s most pressing issues and policies.

Today also brings a pair of columns–in the Wall Street Journal and the Washington Post, respectively–from conservative luminaries defending the notion that Obama has the constitutional power to bomb Libya without congressional authorization. Yoo, the legal architect of George W. Bush’s Terror Presidency, chides Tea Party Republicans like Jason Chaffetz of Utah and Justin Amash of Michigan for questioning Obama’s authority to launch a nondefensive war:

Their praiseworthy opposition to the growth of federal powers at home misleads them to resist Washington’s indispensable role abroad. They mistakenly read the 18th-century constitutional text through a modern lens—for example, understanding “declare war” to mean “start war.” When the Constitution was written, a declaration of war served diplomatic notice about a change in legal relations between nations. It had little to do with launching hostilities. In the century before the Constitution, for example, Great Britain fought numerous major conflicts but declared war only once beforehand.

As commander in chief, the president has the authority to determine when and how U.S. forces are used…. When the Constitution was adopted, the power to “declare war” was not equivalent to permitting the use of military force.

The president certainly can’t derive the authority to bomb Libya from the commander-in-chief clause. As Hamilton explained in Federalist 69, that provision merely indicates that the president is the “first General and admiral” of US military forces. Important as they are, generals and admirals don’t get to decide whether and with whom we go to war.

It’s more common for presidentialists to combine a broad reading of Article II, sec. 1’s “executive Power” with an exceptionally narrow interpretation of Article I, sec. 8’s congressional power “to declare War,” to conclude that the president can start wars, leaving it up to Congress to make it official if they so choose.

One problem with that view is that virtually no one from the Founding Generation seems to have understood the clause in that way. For example, James Wilson told the Pennsylvania ratifying convention that ‘‘this system will not hurry us into war; it is calculated to guard against it. It will not be in the power of a single man, or a single body of men, to involve us in such distress; for the important power in declaring war is vested in the legislature at large.’’ Pierce Butler, like Wilson, had been a delegate to the Philadelphia Convention, and–to the dismay of some delegates–had actually argued for vesting the power to go to war in the president. Yet during the ratification debates, Butler assured the South Carolina legislature that the proposed constitution prevented the president from starting wars: ‘‘Some gentlemen [i.e., Butler himself] were inclined to give this power to the President; but it was objected to, as throwing into his hands the influence of a monarch, having an opportunity of involving his country in a war whenever he wished to promote her destruction.’’

Every major figure from the founding era who commented on the matter said that the Constitution gave Congress the exclusive power to commit the nation to hostilities. Notably, this included not only people with reservations about presidential power, such as James Madison and Thomas Jefferson, but also strong advocates of the President’s prerogatives, such as George Washington and Alexander Hamilton.

“How could this be, though,” Ramsey asks, “if Congress has only the power to ‘declare War’, which we may think refers to making a (now-outmoded) formal announcement? Why can’t the President begin a war informally, merely by ordering an attack, without a declaration?” The answer:

…is that in founding-era terminology war could be “declared” either by formal announcement or by military action initiating hostilities. John Locke’s classic Two Treatises of Government from the late 17th century referred to “declar[ing] by word or action.” Blackstone and Vattel, two of the 18th century legal writers most influential in America, also used “declare” in this way…. Johnson’s dictionary gave as one definition of “declare” to “shew in open view” – which, applied to warfare, would obviously encompass military attacks…. Thus in 18th century terms initiating an attack was as much “to declare war” as was making a formal announcement; Congress’ Article I, Section 8 power is not narrowly about issuing formal announcements, but broadly about authorizing the sorts of actions that begin war.